| A | B |
|---|
| Natural Selection | Those individuals whose characteristics are best suited for their environment tend to survive and produce offspring. |
| Niche | An organism's particular role, or how it makes its living. |
| Competition | The struggle between organisms to survive in a habitat with limited resources. |
| Predation | An interaction in which one organism hunts and kills another for food. |
| Predator | The organism that does the killing. |
| Prey | The organism that is caught. |
| Symbiosis | A close relationshop between two species that benefits at least one of the species. |
| Mutualism | A relationship in which both species benefit. |
| Commensalism | A relationship in which one species benefits and the other species is neither helped nor harmed. |
| Parasitism | One organism living on or inside another organism and harming it. |
| Parasite | The organism that benefits from living on or inside a host. |
| Host | The organism that the parasite lives on or in. |
